_________________"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

The tipping point of overpopulation to crash has passed. The tipping point of methane self release was in an article by 3 groups of tundra scientists posted here in 2009, and will be completely passed by 2020.Soils at the time of die off will be at 90% gone, and aquifers, too. The only thing that could stop all of it is the super volcanic eruption of Yellowstone. Ten years of volcanic winter.Come on, blow baby blow!!!

Actually it was in two articles, one by Alaskan tundra scientists and climatologist, and the othe by 2 groups of Russian tundra scientists and climatologists. The Russians used very large rubber sheets to try to capture the methane, but they were unsuccessful--too much leakage and just too much area to try to cover. Previous attempts to mine the oceanic methane hydrate deposits led to explosive releases with just a few pounds of mechanical force. The stuff will release explosively with a 2* sudden rise in temperature, and in 2009 Norwegian ocean scientists noted the warming off their continental shelf was +1*F down to 700 meters and methane was slowly bubbling out to be dissolved in shallower waters. AGW has been known since 1981, and absolutely irrefutable since before 2005, really 1992, IMO. Arguments are illogical. Not reducing emissions to safe levels for this long has been downright sinful. Instead of denying reality, people should have one child and go solar, NOW!!! It is stupid to waste time arguing when in 2006 we were given 10 years. Every year wasted brings the likelihood of future thermageddon higher. Denialists would never make good pilots, especially instrument rated ones. They would hit the hidden mountain they thought they would miss.

_________________"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

I see you have trouble with context. The IMPACTS of climate change in history have been shown to cause mass extinctions in the past, which was the point being discussed in this series of posts. The change in climate may not make for a pleasant planet on which to live for many speices. In fact, it is possible many of the species may just stop living on the planet as a result.

_________________With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none” Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."Albert Einstein

I see you have trouble with context. The IMPACTS of climate change in history have been shown to cause mass extinctions in the past, which was the point being discussed in this series of posts. The change in climate may not make for a pleasant planet on which to live for many speices. In fact, it is possible many of the species may just stop living on the planet as a result.

And so far, there is no evidence for a negative impact with species with current climate change. An additional 1-2 Degree C increase in temperatures might actually be beneficial for the planet as a whole. Of course, the planet won't warm nearly that much in the future, but such a hypothetical warming would be beneficial.

And so far, there is no evidence for a negative impact with species with current climate change. An additional 1-2 Degree C increase in temperatures might actually be beneficial for the planet as a whole. Of course, the planet won't warm nearly that much in the future, but such a hypothetical warming would be beneficial.

I could list quite a few rodent/lagomorph species who are declining rapidly due to weather (because I am interested in rodents... marmots and pikas being two key groups of species... rainy weather is a key issue for those) and I have heard of polar-region animals having trouble due to lack of ice (polar bears need to eat seals who come to ice holes to breath and baby seals need to live on ice for their first couple weeks and arctic foxes travel to islands over ice to harvest bird eggs and chicks...walruses, some whale species, some fish are also found to be affected by the ice issue). Many of the species I have not mentioned here that are affected by weather are also affected by other man-made issues so it is less clear that their declines are from weather as well as the other issues we know about.

And so far, there is no evidence for a negative impact with species with current climate change. An additional 1-2 Degree C increase in temperatures might actually be beneficial for the planet as a whole. Of course, the planet won't warm nearly that much in the future, but such a hypothetical warming would be beneficial.

I could list quite a few rodent/lagomorph species who are declining rapidly due to weather (because I am interested in rodents... marmots and pikas being two key groups of species... rainy weather is a key issue for those) and I have heard of polar-region animals having trouble due to lack of ice (polar bears need to eat seals who come to ice holes to breath and baby seals need to live on ice for their first couple weeks and arctic foxes travel to islands over ice to harvest bird eggs and chicks...walruses, some whale species, some fish are also found to be affected by the ice issue). Many of the species I have not mentioned here that are affected by weather are also affected by other man-made issues so it is less clear that their declines are from weather as well as the other issues we know about.

Species loss from habitat destruction is a real and definite concern, but from climate change? Temperatures in the Tropics have not risen very much over the last 30 or so years (I assume this is the area you are talking about, since it is the part of the globe that get the most rainfall) (~0.3 Degrees C) so it is unlikely that the species that you are referring to are suffering from extreme temperature changes.

The polar bear populations are currently at a record high, and there is no evidence that they will go extinct in the near future, with temperatures being higher than the present in the past, and polar bears were known to survive that past warming, they can just as well survive this current warming.

I see you have trouble with context. The IMPACTS of climate change in history have been shown to cause mass extinctions in the past, which was the point being discussed in this series of posts. The change in climate may not make for a pleasant planet on which to live for many speices. In fact, it is possible many of the species may just stop living on the planet as a result.

And so far, there is no evidence for a negative impact with species with current climate change. An additional 1-2 Degree C increase in temperatures might actually be beneficial for the planet as a whole. Of course, the planet won't warm nearly that much in the future, but such a hypothetical warming would be beneficial.

You are sorely mistaken in that claim. The change in te4mperature zones is happneing too fast for the adaptation of the plant species and the range is shrinking dramatically. the lack of cold weather is also expanding the range of pests which are also having a severe impact on some species of plants.

The recent large-scale dieback of piñon (Pinus edulis Engelm.) and ponderosa pine (P. ponderosa Dougl. ex Laws.) and associated bark beetle outbreaks in the Southwestern United States has been linked to the ”climate change type drought” (e.g., dry and warm) that occurred in this region in the early 2000s. Several bark beetle species, including piñon ips (Ips confusus Leconte), Arizona fivespined ips (Ips lecontei Swaine) and the western pine beetle (Dendroctonus brevicomis LeConte), responded to the vast landscapes of drought-stressed trees, contributing significantly to the widespread tree mortality. Because elevated temperatures potentially influence the number of generations of these species reproducing in a single year, similar outbreaks could occur again as precipitation and temperature patterns continue to shift.

We have database models to describe and project the effect of temperature, but not other climate variables, on life-cycle timing of the mountain pine beetle and spruce beetle (D. rufipennis Kirby). For both species, the influence of elevated temperatures on outbreak dynamics is most notable at higher elevations and latitudes where some beetles have shifted to completing their development in a single year (univoltine) rather than 2 or even 3 years. Assuming other inputs to the system remain constant, this decrease in generation time translates to a doubling in the rate of population growth.

Model predictions suggest that the greatest risk to spruce forests in the next 30 years will be in Alaska, where elevated temperatures caused outbreaks of spruce beetles in the mid 1990s, and at the highest elevations of the Western States where spruce (Picea spp.) grows. Proportionately, mountain pine beetles in high-elevation five-needle pine forests will also continue to increase. At low elevations, however, under a conservative climate change scenario, the amount of area in which we predict that mountain pine beetle populations will do well in the next 30 years could actually decrease as temperatures warm excessively and disrupt the insects’ seasonality. These predictions, however, are based on model simulations that assume a population must be 100 percent univoltine to be successful. Recent field data suggest mountain pine beetle outbreaks occur in forests with a mix of univoltine and semivoltine (2 years required for a single generation) beetles, and 100 percent univoltinism is not necessarily a requirement. We are revising our phenology model to address these issues.

_________________With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none” Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."Albert Einstein

The polar bear populations are currently at a record high, and there is no evidence that they will go extinct in the near future, with temperatures being higher than the present in the past, and polar bears were known to survive that past warming, they can just as well survive this current warming.

A record high from nearly being hunted into extinction really makes your case .....

I believe there is some disagreement over whether the temperature has been higher than the present during the period in whihc polar bears evolved, and there is no guarantee they can survive this one if the emperature rises too high.

The new genetic data indicate that polar bears went through tough times over the course of their 600,000 year‐old evolutionary history. Polar bears show much less genetic diversity than brown bear. This is probably due to dramatic reductions in population size in the past. Maybe those times coincided with phases of climatic warming. Whether polar bears will be able to survive the current phase of sea ice melting is not clear. Firstly, human impacts are accelerating the rate of climate change, and the arctic could reach higher temperatures than in previous interglacial warm phases. In addition, numerous human‐related issues are threatening the polar bear today.

Polar bears colonizing coastal regions due to sea ice melting frequently encounter human habitat, and many bears are killed. Besides persecution, polar bears are also facing other ‐ evolutionarily novel ‐ threats, including pollution by persistent chemicals in the food chain. "If we were to lose polar bears in our era, we would have to ask ourselves what role we played in pushing them over the edge. They clearly were able to survive previous warm phases," Hailer concludes upon the wider implications of the study.

_________________With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none” Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."Albert Einstein

marmots and pikas being two key groups of species... rainy weather is a key issue for those)

Snowy123 wrote:

Tropics have not risen very much over the last 30 or so years (I assume this is the area you are talking about, since it is the part of the globe that get the most rainfall)

nope... it is the rather dry mountains where marmots and pikas live. They need a clear view of mountain meadows to avoid predators so live above the tree-line or where snow avalanches have prevented tree growth. They have very few days to gather, dry and store hay for the winter and rain/sleet/snow keeps them underground and causes rot in their hay stores. The warming has also moved the treeline up mountains leaving many populations without meadows to move to and they go extinct (many individual mountains have unique subspecies) The mountain weather in the northern areas of North America, Europe, and Asia was the first areas to show changes (as early as the 1940s)

Snowy123 wrote:

The polar bear populations are currently at a record high, and there is no evidence that they will go extinct in the near future

Polar bears have the option of eating other animals and evidence is that a large portion of Grizzly and Polar bears are cross-breeding. The result will be a more grizzly-like version of the polar bear eating caribou/reindeer and elk and following them into human areas and requiring them to be shot (they will kill humans hiding in houses and cars). Without ice, they stand around on the shore for 2-3 months in the summer and live off body fat... waiting to eat seals and walrus pups. That natural habit will have to change.

It is too bad those posts about the tundras being at the tipping point of methane self release from 2009 were lost. I asked admin about it and they were irretrievable. I only found one left on google some time back.PETM was such an event, geologically. There was a period of over 10,000 years of increased vulcanism which gradually (much slower than today), drove the atmospheric CO2 levels higher. Of course, much of it was mitigated by the high atmospheric aerosols amount. With the number of volcanic events, it is assumed there were other seismic events that were increased. It is a good conjecture that a large oceanic earthquake caused a huge undersea slide to a clathrate rich area, causing an explosive release of massive amounts of methane.Either that, or the settling out of particulates led to warmer oceans and arctic tundras which both eventually released all their methane hydrates through temperature gain. The 2009 Norwegian oceanic results showed it vaporizing even at +1*F, but +2*F is where the vaporization becomes rapid. There is ocean bottom evidence of some clathrate fields explosive releases from seaquakes, but that is nothing compared to if the entire ocean warms up 2*F. The effect would be 1,200 feet, then deeper deposits as they warmed. The tundra releases are much greater than the present atmospheric carbon, and the oceans similar. The oceans take about 1,000 years to warm that much, or more. Still, the process today, in the Anthropocene Epoch, is at least ten times the rate of PETM. That is where the adaptability issue comes in. The vast majority of species can not adapt to PETM type conditions in that rapid a time frame. PETM caused a species loss of 30% in ten times the time. With the already high background extinction level from human activities (considered an ELE by Leakey), this event is estimated to be up to a 90% species loss. Some articles I read estimated 80%. This is still greater than the estimated 75% species loss of the Yucatan asteroid event.The possibility of tundra methane self release and its consequences are ignored by many climatologists and denialists. Either they ignore something so horrible or dismiss it out of lack of knowledge. Certainly even a 2*C AGW is bad enough on crop production, and extreme weather destruction. The fact is that the 2*C is also over the amount needed to cause tundra, followed by oceanic, methane self release, AETM and ELE completion.I have written a lot about the population crash of 2050 or before. That is a bad thing, too. I think it is too late to stop. This ELE is far worse, and something we MAY be able to stop with quick sufficient action. Back in 2006, we were given 10 years to go to massive fossil fuel burning reduction. Then later, by 2020. I have read where this is still only a 50% probability of success. It would have been better odds if action was taken back when the stopping of ozone depleting chemicals was done.You can argue all you want and put your head in the sand about what humanity is doing to the long term viability of our biosphere. Time is still running out until the hourglass top is empty, just like it did for going to 1 child families to stop the crash.In a normal crash, the survivors would slowly build back up and stay around long term sustainable level. Passing the tundra methane self release tipping point will lead to a biosphere where humans can not survive, along with 80-90% of the species they depend on. Humans made it through a bottleneck of several thousand years, back when Toba erupted 76K years ago. This is worse by a long shot.I can not understand people doing what they have done, seeing we knew some of it on the first Earth Day. Around that time, I got a pass to Saigon with a friend in my unit, to investigate the stinking Black River of Saigon we had to fly high over when we had missions south. I saw houses on poles over the river with ladders/steps leading down. A woman was washing dishes and filling a rice pan, with her young son bathing nearby. Out of a hole in the bottom of the hut fell a turd about 12 feet or so away. They, supposedly intelligent humans, were using the river as a sewer, for drinking, and for washing, and it stunk bad up to 5,000 feet over it.People all over the world, are doing something similar but not so easily seen or direct. All my proselytizing about overpopulation for over 40 years, AGW for 17 years, and building a solar house, Earthship, and composting and driving a hybrid, with one child now 24, has had no effect at all. The world is heading to hell in a hand basket because of those who deny overpopulation and AGW, et al, and refuse to act out of greed, selfishness, stupidity, or lust.The time to act is now, to mitigate what will happen. The tipping points may be now, or get crossed, but it is in the self interest of our species to at least try.

_________________"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

I think the replies have covered the idea that a tipping point is dramatic but what my question was trying to focus on was;

What mechanisim is about to cause one of these tipping points?

Do you mean the mechanism that causes the extinction domino, which would be the rapid warming of the planet bringing about changes in climate faster than species can adapt or the mechanisms causing the rapid warming, which would primarily be the increased GHGs in the atmosphere.

_________________With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none” Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."Albert Einstein